HLSL: add precise keyword

Test/baseResults/hlsl.precise.frag.out

+hlsl.precise.frag
+Shader version: 450
+gl_FragCoord origin is upper left
+0:? Sequence
+0:8  Function Definition: MyFunction(f1;vf3; (global void)
+0:6    Function Parameters: 
+0:6      'myfloat' (noContraction in float)
+0:6      'myfloat3' (noContraction out 3-component vector of float)
+0:15  Function Definition: main( (global structure{noContraction temp 4-component vector of float color})
+0:9    Function Parameters: 
+0:?     Sequence
+0:11      move second child to first child (noContraction temp 4-component vector of float)
+0:11        color: direct index for structure (noContraction temp 4-component vector of float)
+0:11          'ps_output' (temp structure{noContraction temp 4-component vector of float color})
+0:11          Constant:
+0:11            0 (const int)
+0:11        Constant:
+0:11          1.000000
+0:11          1.000000
+0:11          1.000000
+0:11          1.000000
+0:12      Branch: Return with expression
+0:12        'ps_output' (temp structure{noContraction temp 4-component vector of float color})
+0:?   Linker Objects
+0:?     'precisefloat' (noContraction global float)
+
+
+Linked fragment stage:
+
+
+Shader version: 450
+gl_FragCoord origin is upper left
+0:? Sequence
+0:8  Function Definition: MyFunction(f1;vf3; (global void)
+0:6    Function Parameters: 
+0:6      'myfloat' (noContraction in float)
+0:6      'myfloat3' (noContraction out 3-component vector of float)
+0:15  Function Definition: main( (global structure{noContraction temp 4-component vector of float color})
+0:9    Function Parameters: 
+0:?     Sequence
+0:11      move second child to first child (noContraction temp 4-component vector of float)
+0:11        color: direct index for structure (noContraction temp 4-component vector of float)
+0:11          'ps_output' (temp structure{noContraction temp 4-component vector of float color})
+0:11          Constant:
+0:11            0 (const int)
+0:11        Constant:
+0:11          1.000000
+0:11          1.000000
+0:11          1.000000
+0:11          1.000000
+0:12      Branch: Return with expression
+0:12        'ps_output' (temp structure{noContraction temp 4-component vector of float color})
+0:?   Linker Objects
+0:?     'precisefloat' (noContraction global float)
+
+// Module Version 10000
+// Generated by (magic number): 80001
+// Id's are bound by 29
+
+                              Capability Shader
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main"
+                              ExecutionMode 4 OriginUpperLeft
+                              Name 4  "main"
+                              Name 13  "MyFunction(f1;vf3;"
+                              Name 11  "myfloat"
+                              Name 12  "myfloat3"
+                              Name 16  "PS_OUTPUT"
+                              MemberName 16(PS_OUTPUT) 0  "color"
+                              Name 18  "ps_output"
+                              Name 28  "precisefloat"
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypePointer Function 6(float)
+               8:             TypeVector 6(float) 3
+               9:             TypePointer Function 8(fvec3)
+              10:             TypeFunction 2 7(ptr) 9(ptr)
+              15:             TypeVector 6(float) 4
+   16(PS_OUTPUT):             TypeStruct 15(fvec4)
+              17:             TypePointer Function 16(PS_OUTPUT)
+              19:             TypeInt 32 1
+              20:     19(int) Constant 0
+              21:    6(float) Constant 1065353216
+              22:   15(fvec4) ConstantComposite 21 21 21 21
+              23:             TypePointer Function 15(fvec4)
+              27:             TypePointer Private 6(float)
+28(precisefloat):     27(ptr) Variable Private
+         4(main):           2 Function None 3
+               5:             Label
+   18(ps_output):     17(ptr) Variable Function
+              24:     23(ptr) AccessChain 18(ps_output) 20
+                              Store 24 22
+              25:16(PS_OUTPUT) Load 18(ps_output)
+                              ReturnValue 25
+                              FunctionEnd
+13(MyFunction(f1;vf3;):           2 Function None 10
+     11(myfloat):      7(ptr) FunctionParameter
+    12(myfloat3):      9(ptr) FunctionParameter
+              14:             Label
+                              Return
+                              FunctionEnd

Test/hlsl.precise.frag

+
+struct PS_OUTPUT { precise float4 color : SV_Target0; };
+
+precise float precisefloat;
+
+void MyFunction(in precise float myfloat, out precise float3 myfloat3) { }
+
+PS_OUTPUT main()
+{
+    PS_OUTPUT ps_output;
+    ps_output.color = 1.0;
+    return ps_output;
+}
+

gtests/Hlsl.FromFile.cpp

@@ -123,6 +123,7 @@ INSTANTIATE_TEST_CASE_P(
         {"hlsl.numericsuffixes.frag", "main"},
         {"hlsl.overload.frag", "PixelShaderFunction"},
         {"hlsl.pp.line.frag", "main"},
+        {"hlsl.precise.frag", "main"},
         {"hlsl.promotions.frag", "main"},
         {"hlsl.sample.array.dx10.frag", "main"},
         {"hlsl.sample.basic.dx10.frag", "main"},

hlsl/hlslScanContext.cpp

@@ -463,6 +463,7 @@ EHlslTokenClass HlslScanContext::tokenizeIdentifier()
     case EHTokIn:
     case EHTokOut:
     case EHTokInOut:
+    case EHTokPrecise:
     case EHTokLayout:
         return keyword;